A connecting rod assembly is used for connecting a piston to a crankshaft in an internal combustion engine. The connecting rod assembly typically includes a connecting rod which is attached to a cap using a plurality of bolts. The connecting rod includes a first end which is attached to a piston using a piston pin. The opposite end includes a yoke with a semi-circular bearing portion which mates with a corresponding semi-circular bearing portion in the cap to define an opening for receiving the crankshaft therein. Typically, each bolt includes a head at one end and an opposite end which is threadingly engaged with a nut. To attach the cap to the yoke, it is necessary to place a wrench on both the head and the nut while tightening the nut to prevent rotation of the bolt. However, for certain applications it may be difficult or nearly impossible to access the bolt head to prevent rotation of the bolt.
It is also known to provide the connecting rod with a bolt seat against which the bolt head engages. The bolt seat must be machined into the connecting rod and therefore a small fillet with a transverse surface exists adjacent to the bolt seat. It is known to provide the bolt head with a non-circular cross section which engages the fillet or transverse surface adjacent the bolt seat to prevent rotation of the bolt while tightening the nut. However, the peripheral edge of the bolt which engages the fillet and/or transverse surface adjacent to the bolt seat may cause undesirable stress concentrations in the connecting rod which may result in deformation or damage to the connecting rod.
The present invention is directed to overcoming one or more of the problems as set forth above.